Rotary engine.



' Patented Apr. I, I902. M. J. HEWLETT.

ROTARY ENGINE.

Application filed Oct. 28. 1900.]

3 Sheets-She et I.

(No Model.)

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No. 696,904. Patented Apr. I, I902;

M. J. HEWLETT.

ROTARY ENGINE.

Apphcatlon filed Oct 26 1900 3 Sheets-Sheet 2.

(-No Model.)

Maddya JflemZeiZ' wi/tmm Patented Apr. I, I902. M; J. HEWLETT. ROTARY ENGINE.

(Application filed Oct. 26; 1900.)

a sheets-s am 3.

' (lhfllludeL) Wiimaww UNITED STATES PATENT @Frron'.

MADDRA J. HEWLETT, OF KEWANEE, ILLINOIS, ASSIGNOR OF ONE-HALF TO ALFRED M. IIEIVLETT, OF KEVVANEE, ILLINOIS.

ROTARY ENGINE.

SPECIFICATION forming part of Letters Patent No. 696,904, dated April 1, 1902.

Application filed October 26, 1900. Serial No. 34,491. (No model.)

To all whom it may concern.-

Be it known that I, MADDRA .I. HEWLETT, a citizen of the United'States, residing at Ke Wanee, in the county of Henry and State of Illinois, have invented a new and useful Rotary Engine, of which the followingis a specification. V

My present invention relates to a novel motor or other analogous translating device.

In order that the invention and the special utility underlying it may be better comprehended, attention maybe called to the fact that motors, air-compressors, pumps, or other translating devices embodying rotary pistons driven by a motive fluid orsubjected to back pressure exerted thereby have been more or less unsatisfactory, particularly in connections where the direct or back pressure is necessarily great. The truth of this statement is particularly apparent to those familiar with the development of rotary engines,and theprincipal reason underlying this debility of translating devices of this character is that the rotary member or piston is not only subjected to pressure in theline of movement of its periphery, but is also subjected to a corresponding side pressure exerted toward its axis. This will be more clearly apparent when we consider that in devices of the type mentioned the rotary member is driven by the impact of the motive agent against blades or heads extending radially from its periphery or against substantially radial abutment-s formed by recessing the periphery of the member. It follows, therefore, that the liberation of an expansive fl uid in effective proximity to this member or piston will necessarily exert what is known in the art as side pressure, tending to createa degree of friction between the rotary piston and its shaft or between the shaft and the shaft-bearings, increasing in like ratio as the effective pressure of the motive agent is increased. The same result is noticeable when the rotary member, instead of being driven by an expansive agent under the direct pressure thereof, as in rotary engines, is employed, for. instance, for compressing air or for pumping water, because in these relations the fluid compressed or pumped exerts a back pressure, which to all intents and- A striking evidence of this fact is the common necessity for turning over a rotary engine manually or otherwise after the throttle has-been opened in order to secure its response to the introduction of the motive agent.

Having in mind, therefore, the elimination of this objectionable element in engines or other translating devices of the rotary type,

the object of my invention is to produce a simple and effective construction by means of which a counteractive pressure may be opposed to the side pressure of the fluid directed against the outer periphery of the piston, and, further, to so organize and arrange a series of rotary elements as to totally eliminate the objectionable side pressure defined, to provide for a decrease of the area of the pistons in frictional contact with the sides of the easing, and to include in such a device a novel form of controlling-valve serving to regulate, either automatically or otherwise, the supply of a motive agent to the motor.

To the accomplishment of the several objects stated, the invention consists in the construction and arrangement of parts hereinafter fully described, illustrated in the accompanying drawings, and succinctly defined in the appended claims.

In said drawings, Figure 1 is a sectional elevation of what is perhaps the simplest embodiment of my invention. Fig. 2 is a'similar View of a variation which comprehends an increase in the number-of radial heads upon the center piston, the inclusion of a novel controlling-valve, and the addition of a supplemental steam-induction port intended to be utilized to start the motor. Fig. 3 is still another variation, the peculiarities of which will be defined hereinafter. Fig. 4 is a similar view of still another variation. Fig. 5 is a sectional view on the line 5 5 of Fig. 4,

and Fig. 6 is a detached view of one ofthe casing-heads.

Referring to the numerals employed to designate corresponding parts throughout the views, but having more general reference at present to the structure shown in Fig. 1 of the drawings, 1 indicates the casing of a rotary engine, which type of translating devices I have selected for the purpose of illustrating the application of my invention. This casin g is given any requisite form in accordance with the number and relative proportions of the rotary members, which in this instance are embodied in the piston-wheels 2, 3, and 4. The several wheels are mounted within the casing 1 upon-shafts 2, 3, and 4, which are provided with suitable bearings in the oppo site sides or heads 5 and 6 of the casing and are geared to a driving-shaft 7as, for instance, in the manner shown in Fig. 5 of the drawings. In this embodiment of the device the center piston 3 has its periphery in contact with the periphery of the end pistons 2 and 4 and is provided at diametricallyoppositepoints with a pair of radially -extending piston heads or blades 8 and 9, arranged to extend into peripheral recesses 8 and 9 and 8" and 9 in the piston-wheels 2 and 4, respectively. The heads 8 and 9 are designed to receive the impact of steam or other motive agent to effect the rotation of the center wheel and through it the end wheels 2 and 4, and it is therefore necessary to define a closed steam-space through whichthe heads may move when passing from one side to the other, or, in other words, between their points of engagement between the end wheels or pistons. This steamspace, or, more properly speaking, these steam-spaces lO and 11, I define by mounting a pair of head-blocks 12 and 13 within the casing and extending between the heads with their concave faces concentric with the periphery of the wheel 3, but ata sufficient distance therefrom to have steamtight engagement with the outer ends or faces of the heads 8 and 9 as the latter are impelled under steamer-other pressure. One end of each head-block is disposed in steam-tight connection with the periphery of an end wheel or piston, and at the other end of each block is formed an exhaust-passage 14 or 14", designed to lead the steam from the steamspaces to the exhaustports 15 and 16 through the wall of the casing.

Anticipating for amoment the description of the means which I employ for effecting the introduction of the motiveagent to the inte rior of the casing, it will be noted that the liberation of steam or other expansive fluid within the steam-spaces will be effected immediately behind the heads 8 and9, assuming the parts to be positioned as in Fig. 1. The adjacent contacting portions of the walls or peripheries of the. wheels will constitute an abutment confining the steam for the effective exertion of its pressure against the heads, which are shown as just entering the at the farther ends thereof; but it will also appear that the pressure which is exerted upon the head to drive the center wheel or piston will be exerted in like degree upon the peripheries of the several wheels in the directions of or rather toward their axes. The effect of this upon the center wheel will be to balance it, inasmuch as the pressure of the steam occluded in each steam-passage will exert corresponding side pressures in opposite directions at diametrically opposite points; but no such desirable counteraction is exerted upon the end wheels or pistons for the reason that at a point diametrically opposite the point of exertion of pressure thereon these wheels are either subjected to no steam-pressure at all or are opposed to clearance-spaces in communication with the exhaust, and consequently containing either no motive agent or only such as will exert no effective counteractive pressure. g It is evident, therefore, that there will be a side pressure or thrust exerted upon the bearings of the shafts 2' and 4,creating an obstructive friction corresponding to the steam-pressure, and it will therefore follow that a large proportion of the energy designed for translation will be con sumed in overcoming this frictional resistance to the operation of the motor, and it will be equally clear that the elimination of this friction will correspondingly increase the capacity and range of utility of the engine. The manner in which I effect the elimination of this objectionable feature is by subjecting the piston proper, which is obviously the cylindrical rim of each piston-wheel, to an internal pressure opposed. by counteraction to the external pressure exerted by the steam occluded in the steam-space. The precise manner in which this internal counteractive pressure is secured is susceptible of Variation between widely-separated limits, as

I will hereinafter show; but a simple mannor of accomplishing the desired end'consists in forming each piston-wheel with a cylindrical rim or piston proper, 16, encircling a medially-disposed web 17, having a hub 18 pierced by and secured upon a shaft, as shown. This form of piston-wheel will present an open-ended cylindrical piston adapted for the introduction or insertion of what may be termed internal steam-chests 19 and 20, extended into each end of each end piston from each of the casing-heads, the inner ends of the chests terminating at or adjacent to the web of the wheel, as shown more clearly in Fig. 5 of the drawings. In cross-sectional contour the internal valve-chests are generally arcuate, inasmuch as they must fit snugly against the interior face of the piston and must be so formed as not to contact with the adjacent hub. Each of these chests is provided with a steam-chamber 21, the outer side or wall of which is cut away and is closed by the piston in order that the steam within the chest will exert a pressure directly against LFI the interior face of the piston at a point opposite the external pressure exerted by the steam within the steam-space. Obviously, therefore, as'the steam-chest is carried by a stationary partof thestructnre counteractive pressure will be exerted upon the piston of each end wheel and the several pistons Will be relieved of the friction due to side thrusts and will all be balanced to facilitate the translation of a maximum percentage of the energy exerted by the motive agent. In like manner it the invention is embodied in a pump or compressor wherein the fluidinstead of acting upon the pistons is acted upon thereby the beneficial result will be the same, inasmuch as counteractive pressures are exerted to the same end, whether they are direct or back pressures. So far as this broad aspect ofthe invention is concerned it is immaterial how the steam or other motive agent is introduced to the steam-chest or to the steam-spaces; but in Fig. 1 ofthe drawings I have shown a construction which comprc hends the initial introduction of the steam to the chambers 21 of the valve-chests through main induction-ports 22 and 23, piercing both heads of the engine-casing and in communication with'the steam-supply pipes. In this form the steam is led from the chambers 21 through piston-ports24 and 25, piercing the walls of the pistons and opening into the recesses provided for the'reception of the heads upon the center wheel. The steam is not permitted to escape to the steam-passagesexcept when the piston-ports arrive opposite the open sides of the steam-chests, which latter are therefore so positioned that the induction of the steam to the steam-spaces will occur 3' ust as the heads have left the recesses in the end pistons andhave entered the steam-spaces. This peculiar arrangement is alsoproductive of another usefulresult, as it will be seen that the steam is out off as soon as the recess is closed by being moved into opposition to that part of the contiguoushead-blo'ck which is in contact with the periphery ofthe piston,

and after the recess passes thehead-blockthe piston-port will have passed the opening'of the steam-chest and will consequently remain out of communication with the steam-supply until it again arrives at the end of the steampassage. Therefore the period of steam-induction to the steam-spaces is of brief duration, and as a consequence the steam will be used expansively through a considerable portion of the movement of each head.

In Fig. 2 of the drawings I have shown a variation of the structure just described; but aside from the mere addition of a number of heads upon the center wheel a corresponding number of peripheral recesses and ports in the end wheels and changes of proportion necessitated thereby the variation only enibraces the addition of controlling-valves26 and 27 within the steam-chests andjof an auX iliary steam-induction port 28 in one of the steam-spaces, said port being provided merely for the purpose of starting the engine in the event of its having stopped in aposition which will leave all of the piston-ports out of communication withthe chambers of the valvechests. The controlling-valves 26 and 27 slide Within the chambers 21' and are designed to control the closure of the main inductionports 22 and 23 for the purpose of regulating the supply of steam or other motive agent to the engine. The particular means employed foractuating these valves is not essential; but such means may comprehend a rock-shaft 28,carrying an oscillating arm 29, engaging a recess in the valve and designed to be operated in any suitable manneras, for instance, by governor mechanism which, in a manner Well understood in the art, will control-the position of the valve and insure such regulation of the steam-supply as will economize the consumption of the motive agent by regulating the steam pressure in a manner correspondingto the load opposed to the engine or the work to be donethereby.

In Fig. 3 of the drawings I have illustrated a variation of the structure shown in Fig. 1 similar to that shown in Fig. 2, except that the controlling-valves are omitted and the steaminstead of being led initially into the chambers of the valve-chests is led directly to the steam-spaces through induction-ports 30 and3 l, piercing the head-block. In this form the internal steam-chests are provided with steam from the steam-spacesthrough supplemental ports 32 and*33, formed inthe heads of the casing, as clearly showninFig. It will be noted that the fundamental ideato \Vlli,hh6 proper balancing of the end pistons only distinction-being that in the first twoinstances the steam is admitted initially tothe internal steam-chests," from whence it issupplied to the steam-spaces surrounding the center piston,while in thelast instance the motive agent is supplied'directl y tothe' steam-spaces and is thence led'to theinterior of the chests to secure the proper counteractive pressure.

In Figre'of the drawings I have illustrated a still f urther' variation which consists in so greatly augmenting the number of'heads upon the center 'Wheel and the recessesin the end Wheel as to produce, in ede-ct, a'series of wheels or pistons having intermeshing radial teeth.

It will be noted that in this construction I do I notdepend upon the engagement of the teeth with 'each' other to form the abutment: -On the contrary, 1 form the outer faces of these teeth 34 of each wheel upon atruecircle to cause them to'abut and have steam-tight connection or contact with the'peri-pheral face of the opposed piston-wheel.

Another feature of the invention which I consider important and which maybe common to the several formsshown is'the provision of what'ma'ybe termed wear-plates .35, (best seen inFigs.*5 and f the draw ings,) oonstitutingend abutments extending from the heads of the casing and in steamtight contact-with the ends of the pistons and constituting the end walls of the steam-spaces. The purpose of these wear-plates is to maintain the steam-tight relation through those periods of travel of the heads during which the latter are under steam-pressure and permitting the remaining portion of each piston to move freely and with considerable clearancebetween them and thelwalls .ofthe casing for the purpose of reducing the frictional 'area of the working parts;of the engine to the minimum. It is evident that where these wear-plates are employed the auxiliary ports 32 and 33 are formed therein instead of in the ends or heads of thecasing.

From the foregoinglit will appear that I have produced-a simple and effective transla-ting device of the rotaryftype embodying one orany greater numberof rotary members or pistons capable of running under even balance andwith the least possible opposition to the translation of energy exerted into work performed; but while the present embodiment of the invention is believed at this time to be preferable I do not limit myself to the structural details illustrated and described, as it is evident that many changes, 1

modifications, and variations of both form, proportion, and 'arran gement may be effected assuggested by experience and experiment without departing from the scope ofthe protect-ion prayed. 1

What I claim is A 1. A translating device comprising a casing and a series of rotarymembers mounted there- -in and geared together, means for supplying ,fluid to the interior of the casingintermediate of said members toact on the peripheral faces thereof, and means for leading a fluid into contact with the interiorfaces of. the end membersonlyof the series at points opposite the application of external. pressure to said end members. i

2. In a device of the character described, athe combination with acasing provided with head-blocks and with bearing-plates carried by the opposite end walls of the casing, of rotary pistons located-wholly out'of contact with :the end walls of the casing and having .peripheralwcontact with thelhead-blocks and bearing at theirends againstthe bearing- .pl'ates; said bearing-plates being disposed across the opposite ends of the steam-space defined between the pistons, to confine the isteam to such steam-space.

3. A translatin gdevice comprising a casing and a series of rotary pistons, the end pistons of the series being hollow, means for supplying fluid to the interior of the casing intermediate of the pistons, stationary steam-chests extended into each of the end pistons of the series from opposite sides of the casing, and means for supplying steam to the chests, each of said steam-chests having an open wall opposed to the interior face of its piston,

,4. A translating device comprising a casing and a series of rotary pistons, the end pistons of the series being hollow, means forsupplying fluid to the interior of the casing intermediate of the pistons, stationary steam-chests of transversely-arcuate form extended into each of the end pistons from the opposite sides of the casing, and means for supplying steam to said chests, each of said steam-chests having an open wall opposed directly to the interior face of its piston.

5. A translating device comprising a casing anda series of rotary pistons, the end pistons of the series being formed with a central web and a cylindrical rim, means for supplying a motive fluid to the interior of the casing intermediate of the pistons, stationary steamchests of transversely-arcuate form extended into each of the. end pistons from the opposite sidesof the casing and terminating contiguous to the web, and means for supplying a motive fluid to the chests, each of said chests having an open wall opposed to the interior face of theadjacent piston-rim.

(5.. Atranslating device comprising a casing and'a series of rotary pistons, the end pistons of the series being hollow, stationary steamchests extended into the opposite ends of each piston from the opposite sides of the casing, and ports establishing communication between the steam-chests and the steam-space defined intermediateof the pistons, each of said steam-chests having an open wall opposed to the interior face of its piston.

7. ,In a translating device, the combination with a casing provided with head-blocks and bearing-plates, of rotary pistons located out of contact with the walls of the casing and having peripheral contact with the headblocks, and bearing at their ends against the bearing-plates, and steam-chests extended ,into the ends of certain of the pistons and provided with open walls opposed to the interior face of the adjacent piston, certain of said bearing-plates being provided with ports establishing communication between an interiorsteam chest and the steam-space defined between contiguous pistons.

, 8. In a translating device, the combination with a casing, of a rotary center piston pro- .vided with heads, a pair of hollow end pistons geared to the center piston and provided .with peripheral recesses for the reception of the heads, means for supplying a motive .fluid to the interior of the casing intermediate of the pistons to act on the peripheral faces thereof, stationary steam chests extended into the end pistons and having open walls opposed to the interior faces thereof at points opposite the application of external pressure, and means for supplying steam to thesteam-chests.

ICC

' faces thereof, said end pistons being provided with ports establishing communication between the interior of the casing and the interior of the steam-chests to permit the motive fluid to pass into the steam-chests for application to the interior faces of the end pistons at points opposite the application of external pressure to said end pistons.

10. In a translating device, the combination with a casing and means for supplying steam thereto, of a rotary center piston therein provided with heads, a pair of hollow end pistons provided with peripheral recesses for the reexten'ded into the end pistons and having openings opposed to the interior faces thereof, head-blocks located Within the casing and defining steam-spacesfor the passage of the heads, and means for supplying steam to said steam-chests.

11. A translating device comprising a casing and a rotary piston therein, meansfor introducing steam to the interior of the casing to operate the piston, and steam-chests extending into the piston from the opposite sides thereof.

12. A translating device comprising a casing, and a rotary piston therein, means for leading steam to the interior of the casing, transversely-arcuate steam-chests extending into the piston from'the opposite sides thereof, and means for leading steam to the steamchests.

13. In a translating device, the combination with a casing providedwith stationary steamchests extending inwardly from the opposite sides thereof and having open walls, a hollow piston located within the casing and having its peripheral wall disposed opposite the open walls of said steam-chests, and means for leading steam to the casing and steam-chests respectively.

14. A translating device comprising a casing and a hollow piston therein, transverselyarcuate stationary steam-chests extended into the opposite ends of the piston from the opposite sides of the casing and having open walls opposed to the peripheral wall of said piston, and means for establishing'communication between the steam-chests and the interior of the casing whereby steam may be introduced into one of said chambers for the purpose of supplying both.

15. A translating device comprising a casing and a rotary piston therein formed with a central web and a cylindrical rim, and steamchests extended into the opposite ends of the piston and bearing against the web thereof.

16. A translating device comprising a casing and a rotary piston form ed with a central web and a cylindrical rim, stationary steamchests of transversely-arcuate form extended into the piston from the opposite sides thereof and hearing at their inner ends against the web, said steam-chests being provided with open walls opposed to the interior face of the cylindrical rimot' the piston, means for establishing communication between the casing and steam-chests, and means for leading steam into the casing.

17. A'translating device comprising a casing and a plurality of pistons located wholly out of'contact with the walls of the casing, bearing-plates opposed to the ends ofthe pistons and closing the opposite endsof the steam-space defined between the' pistons, a head-block having peripheral contact withthe pistons, and means for introducing steamto the steam-space through the head-block. ception of the heads, stationary steam-chests 18. A translating device comprising a casing and a plurality of pistons located wholly out of contact with the walls'ot' the casing, bearing-plates opposed to the ends of the pistons and closing the opposite" ends of the steam-spaces defined between the pistons, a head-block having peripheral contact with the pistons,means for introducing steamto the steam-spaces through the head-block, and

a stationary steam-chest extending into the piston and provided with an open wall disposed opposite the interior face of the pistonrnn. 1 i i 1 19; A translating device comprising a casing and a plurality of pistons, a stationary steam-chest located within one piston, means forintroducing steam to the interior of' the casing, and-aport located beyond theend of the pistonand'communicating at its opposite.

ends with the interior of the casing and steamchest respectively. i

20. In a translating device, the-combination with a casing and a piston, said piston being -composed of a hub, a Web'and a cylindrical rim, of stationary steam-chests located between the hub and rim and abutting against the web of the piston.

21. A translating device comprising a casing, a series of rotary pistons arranged in 'alinement'within the casing and moving 111 unison, means for supplying fluid toth'e interior of the casing inter-mediate of saidJpistons to act on the peripheral faces -thereof,

steam-chests mounted within theend pistons only of the series and having openwalls opposed to theinteriorfaces of said end pistons at pointsopposite the applicationof external pressurethereto, and means for-supplying steam to saidst-eam-chests. l l

22. In a translating device, the combination with a casing provided withhead-blocka-and with bearing-plates rigidly connected to the inner faces of theopposite endwallsiofthe casing and disposed immecliatelya'djacent to thehead-blocks, of rotary pistons located wholly out of contact with the: end walls of the casing and having peripheral conta'ctwith the head-blocks, and hearing at theirends against the bearing-plates, said bearingplates being disposed entirely across the 0pposite ends of the steam-space defined be- I tween the pistons to confine the steam to said I v 5 steam-space and thus prevent the application \Vitnesses:

of steam-pressure to the ends of the pistons. l HARVEY L..DAY,

In testimony that I claim the foregoing as l R. W. GAMBLE.

the presence of two witnesses.

MADDRA J. HEWLETT.

my own I have hereto affixed my signature in 

